{#
# Macro to render the Google Analytics callback script.
#}
{% macro render_google_analytics_script(google_analytics_id) -%}
  {% if google_analytics_id %}
    <!-- Google Analytics.  This  boilerplate code is as emitted from
         the Analytics page, except that IDs are templated and the
         hostname is taken from the current page, not hardcoded. -->
    <script>
    (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
    (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
    m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
    })(window,document,'script','//www.google-analytics.com/analytics.js','ga');

    ga('create', '{{ google_analytics_id }}', window.location.hostname);
    ga('send', 'pageview');
    </script>
  {% endif %}
{%- endmacro %}